What is the Greatest Common Factor of 21270 and 21285?

Greatest common factor (GCF) of 21270 and 21285 is 15.

GCF(21270,21285) = 15

We will now calculate the prime factors of 21270 and 21285, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21270 and 21285.

How to find the GCF of 21270 and 21285?

We will first find the prime factorization of 21270 and 21285. After we will calculate the factors of 21270 and 21285 and find the biggest common factor number .

Step-1: Prime Factorization of 21270

Prime factors of 21270 are 2, 3, 5, 709. Prime factorization of 21270 in exponential form is:

21270 = 2¹ × 3¹ × 5¹ × 709¹

Step-2: Prime Factorization of 21285

Prime factors of 21285 are 3, 5, 11, 43. Prime factorization of 21285 in exponential form is:

21285 = 3² × 5¹ × 11¹ × 43¹

Step-3: Factors of 21270

List of positive integer factors of 21270 that divides 21270 without a remainder.

1, 2, 3, 5, 6, 10, 15, 30, 709, 1418, 2127, 3545, 4254, 7090, 10635

Step-4: Factors of 21285

List of positive integer factors of 21285 that divides 21270 without a remainder.

1, 3, 5, 9, 11, 15, 33, 43, 45, 55, 99, 129, 165, 215, 387, 473, 495, 645, 1419, 1935, 2365, 4257, 7095

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21270 and 21285. The biggest common factor number is the GCF number.
So the greatest common factor 21270 and 21285 is 15.

Also check out the Least Common Multiple of 21270 and 21285